Laser etching for light-emitting diode devices and related methods

Abstract

Solid-state lighting devices, and more particularly to laser etching light-emitting diode (LED) devices and related methods are disclosed. LED devices that use sapphire substrates are difficult to etch using conventional techniques, but laser etching and ablation of sapphire substrates overcomes these challenges. Laser etching a surface of the sapphire substrate can form light-extraction features that include structures formed in or on light-emitting surfaces of substrates. Light-extraction features may include repeating patterns of features with dimensions that, along with reduced substrate thicknesses, provide targeted emission profiles for flip-chip structures, such as Lambertian emission profiles. In some embodiments, laser ablation of the sapphire substrate can also be used to form trenches between active layer portions of an LED matrix to form pixels that reduce interference between the active layer portions. The trenches can further be filled with materials with light-altering properties to further refine the desired emission characteristics.